1,181 research outputs found
Sexuality and Politics. Lady Morgan and the Morality of the Italians
A study of the book "Italy" published by lady Morgan in 1821, with particular reference to the problem of the sexual morality and of the family life of the Italian
A statistical model with a standard Gamma distribution
We study a statistical model consisting of basic units which interact
with each other by exchanging a physical entity, according to a given
microscopic random law, depending on a parameter . We focus on the
equilibrium or stationary distribution of the entity exchanged and verify
through numerical fitting of the simulation data that the final form of the
equilibrium distribution is that of a standard Gamma distribution. The model
can be interpreted as a simple closed economy in which economic agents trade
money and a saving criterion is fixed by the saving propensity .
Alternatively, from the nature of the equilibrium distribution, we show that
the model can also be interpreted as a perfect gas at an effective temperature
, where particles exchange energy in a space with an effective
dimension .Comment: 5 pages, including 4 figures. Uses REVTeX styl
A probabilistic framework to define the design stress and acceptable defects under combined-cycle fatigue conditions
Abstract Probabilistic routines are necessary to determine the permissible design stress when the operational conditions of traditional gas turbines are further challenged to reach higher performances in terms of flexibility. This paper focuses on the definition of a probabilistic tool aimed to simulate the damage development under combined high and low cycle fatigue conditions considering the stochastic nature of some of the variables introduced in the model. The variables considered in the present study are the long crack threshold Δ K th , LC and the slope of the crack growth law C in the so-called Paris region, the endurance limit Δ σ w 0 and the variability of the applied stress as it cannot be considered a fixed variable in the complex loading scenario of gas turbines. A broad experimental campaign was performed to characterize the material properties in terms of short and long crack resistance under constant and combined cyclic conditions. The data were used to define the average and variance of the materials parameters to feed Montecarlo simulations and, at a target probability of failure, establish the design stress. This work points to determine safety margins which strictly depend on the natural variability of the variables that govern the damage accumulation in the mechanical component
Microeconomics of the ideal gas like market models
We develop a framework based on microeconomic theory from which the ideal gas
like market models can be addressed. A kinetic exchange model based on that
framework is proposed and its distributional features have been studied by
considering its moments. Next, we derive the moments of the CC model (Eur.
Phys. J. B 17 (2000) 167) as well. Some precise solutions are obtained which
conform with the solutions obtained earlier. Finally, an output market is
introduced with global price determination in the model with some necessary
modifications.Comment: 15pp. Revised & a reference added. An appeal in Appendix-annex
(section 8; not for publication) also added. Physica A (accepted for
publication
Basic kinetic wealth-exchange models: common features and open problems
We review the basic kinetic wealth-exchange models of Angle [J. Angle, Social
Forces 65 (1986) 293; J. Math. Sociol. 26 (2002) 217], Bennati [E. Bennati,
Rivista Internazionale di Scienze Economiche e Commerciali 35 (1988) 735],
Chakraborti and Chakrabarti [A. Chakraborti, B. K. Chakrabarti, Eur. Phys. J. B
17 (2000) 167], and of Dragulescu and Yakovenko [A. Dragulescu, V. M.
Yakovenko, Eur. Phys. J. B 17 (2000) 723]. Analytical fitting forms for the
equilibrium wealth distributions are proposed. The influence of heterogeneity
is investigated, the appearance of the fat tail in the wealth distribution and
the relaxation to equilibrium are discussed. A unified reformulation of the
models considered is suggested.Comment: Updated version; 9 pages, 5 figures, 2 table
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